Alignment of surfaces to a curve (loop) or vertex...?
It looks, in this case, as if you should just be able to set your snap to 'Vertex' and 'Active'... select the vertex at the peak last, (so it's the active one) and GY the lot,  hovering over one of the vertices on the central vertical loop to induce the snap.

Either switch on 'Automatically Merge Vertices' in the header before the move, or CtrlVR.. Remove Doubles when you're done.